Master board control
Once you start playing Hearthstone with an eye for competitive play, you'll realise the it's less a game of chance and more a game of numbers. Once you realise that, the way you play the game and view every match up completely changes.
When it comes down to the wire, it's all about board control - forcing the other player to burn more resources dealing with your cards then you spend dealing with theirs. Hitting your opponent with powerful debuffs will force them to use a valuable spell, while attacking a Hero directly will push them to waste resources a powerful card with Taunt. Use the numbers to your advantage and you'll bleed your opponent out with every turn.
Use your Hero class effectively
When you start playing Hearthstone competitively, the Hero at the head of your deck and the cards you surround them with transcend the simple factor of how much you like them. When you get to the really advanced skill levels, you need to have multiple decks on hand, each one tailored for certain play styles.
Mages are often best avoided as they're super popular online - same goes for Warlock as it's one of the stiffest and hardest decks to deploy among the higher echelons of ranked play. Rogues are an ideal choice, thanks to its reliance more on spells and buffs than straight up creature play. It's a riskier choice, but higher level play runs on risk. Druid is another fine choice due to its versatility and core reliance on defence. If you like to play wars of attrition, Druid is the class for you.
Use third-party resources
If you're taking your Hearthstone play to a really competitive level, then you need to have data to hand that shows how you're playing from game to game. There are a whole host of third-party sites, apps and bits of software that effectively track your account and record everything from how often a card is pulled to the average time it takes you to make lethal.
Hearth Arena is one of our favourites, mainly because it offers a variety of resources, including that all important stat tracker, the ability to study the potential uses of your deck and offer advice on drafting picks. The only way to improve your Hearthstone game at this level is to break your plays down to the numbers and refine those mistakes out of your playbook, so make sure you use one of these resources.
Relearn the way of the combo in the Arena
When playing in the Arena you can suffer up to three losses, or rack up a total of 12 wins, before the game forces you to cash your progress in for gold. With this in mind, your time in the Arena can be over in the blink of an eye so you effectively have to dismiss a lot of the principles that serve you well elsewhere in the game.
Take synergy, for example. In normal online play, your deck is built to perform in harmony with itself, but in the Arena cards are 'drafted' from other decks, making it far harder to create a mutually beneficial relationship. You can still perform combos, you just need to think in broader terms rather than simply choosing cards based solely on your type of playstyle.
Learn to farm those bots
Bots in Hearthstone? Still? Yup - they're not as common as they used to be since Blizzard has been clamping down on them, but they do still exist and seeking them out can prove one of the most unconventional ways to farm gold and resources.
Bots are basically AI routines written by advanced players to simulate working accounts - taking one on will provide you a way to play a skill level that's limited in certain ways. Blizzard has understandably banned them, but if you come up against a player with a golden Hero portrait that shows no natural movement (hovering cursors, checking cards, etc) then you've caught an AI. Most of these accounts operate late at night, so be sure to deploy a deck that counters the most popular, aggro-based deck of the month.